<!DOCTYPE html>
<head>
    <script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
    <script>
        const appData = {
            count: 0
        }
        const App = {
            data(){
                return {
                    count: appData.count
                }
            },
            computed:{
                countText:{
                    get(){
                        return this.count * 2 + "次"
                    }
                }
            }
        }
    </script>
</head>
<body>
    <div id="app">
        <button @click="count++">{{count}}</button>
        <p>{{countText}}</p>
    </div>
    <script>
        Vue.createApp(App).mount('#app')
    </script>
</body>
